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Density of states

  1. Dec 7, 2008 #1
    1. The problem statement, all variables and given/known data

    We study a one dimensional metal with length L at 0 K, and ignore the electron spin. Assume that the electrons do not interact with each other. The electron states are given by

    [tex]\psi(x) = \frac{1}{\sqrt{L}}exp(ikx), \psi(x) = \psi(x + L) [/tex]

    [tex]\psi(x) = \psi(x + L)[/tex]

    What is the density of states at the Fermi level for this metal?

    3. The attempt at a solution

    According to my book, the total energy of the system is

    [tex]E = \frac{\hbar^{2}\pi^{2}n^{2}}{2mL^{2}}[/tex]

    why is this?

    It's evident that k = n*2*pi because of the boundary contidions. I don't know what to do next.
    Last edited: Dec 7, 2008
  2. jcsd
  3. Dec 8, 2008 #2


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    Homework Helper

    That doesn't look right to me. What book is this? Isn't that the energy of a SINGLE electron in the energy mode n (not the energy of all of them together)?

    However, I think this expression will still be useful to you, because, since you are ignoring spin, then a single electron fills an energy level, so it represents dE/dN, where N is the number of electrons in the system.
    Last edited: Dec 8, 2008
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